A good credit history allows a person to take a mortgage on a house, rent an apartment, get charge cards, and get a loan for a car or education. A person with a poor credit history either can't get these loans or is stuck paying a very high interest rate. For more information, check this site.
Ability and determination to pay bills is very important to those who lend money, or sell things on credit. Some folks do not have to the ability to pay for all that they want to buy, and some just don't intend to. So for a business that sells things on credit, or a business that loans money, it is vital to screen out those who cant pay, or don't intend to.
What we find in the credit history is the character of the person: do they pay their bills on time.
... and their ability (or inability) to manage their own money can often indicate how they might do with other people's money if they are running for any office, for example -- whether it's for a school board position, a city position, county, state, or national position.
It's part of one's character in a very clearly demonstrated way.